Don't run voltha processes if already running just to avoid multiple running instances.
Change default voltha interface in manifest-voltha to eth0.

Change-Id: I28c19d8c9836e9f5809e1ea12bfcd57b2a596ddc
diff --git a/src/test/setup/manifest-voltha.json b/src/test/setup/manifest-voltha.json
index d73b5d2..1c061a5 100644
--- a/src/test/setup/manifest-voltha.json
+++ b/src/test/setup/manifest-voltha.json
@@ -7,5 +7,5 @@
     "jvm_heap_size" : "1G",
     "karaf_version" : "3.0.8",
     "voltha_loc" : "/home/ubuntu/voltha/incubator/voltha",
-    "voltha_intf" : "enp0s9"
+    "voltha_intf" : "eth0"
 }